This invention relates to captive fastening arrangements.
Such arrangements are commonly used in applications, e.g. on aircraft, where a loose fastener such as a nut could cause severe damage. Captive fastenings may also simplify assembly and maintenance components. For example a rectangular panel may be provided with captive nut assemblies at each corner which are screwed onto studs on an underlying structure. Where a large degree of float is required between the captive fastener and the fastener body, existing arrangements may not provide a satisfactory solution. A requirement for a large degree of float may also make initial engagement of the cooperating fastening elements problematic. The embodiment described herein provides a fastening with relatively large float, captive parts, and relatively easy location between the cooperating elements due to a degree of self alignment between the parts.
British Patents Nos. 1,139,257 and 1,231,723 each show arrangements in which an internally threaded component is held captive within a recess and is prevented from rotating. This type of arrangement requires a loose bolt to be screwed into the nut and is not suitable for use with a fixed bolt or threaded stud which require that the nut be engaged by a tool and rotated to run it down the bolt or stud. Also, the need in the earlier arrangements to prevent rotation of the nut means that the nut is not capable of float relative to the bolt or stud and so any tolerance must be provided by the loose bolt or stud. Further, the use of a loose bolt defies the principle of a captive fastening.